Green
On this page is information about green colours. These are:
- Terre Verte / Green Earth
- Green Cinnabar / Chrome Geen
- Veridian
- Cobalt Green
- Emerald Green
- Scheele's Green
- Malachite
- Verdigris
- Atacamite
Terre Verte / Green Earth
Use - Paint pigment
Formula - K[(Al,FeII),(FeII,Mg)(AlSi3,Si4)O10(OH)2]
Chemical Name - Iron silicate
Structure -
Synthesis - Is obtained from grinding glauconite and celadonite minerals into a fine powder.
Interesting Facts - Found in Roman wall paintings and in the ruins of Pompeii.
Green Cinnabar / Chrome Green
Use - Paint pigment
Formula - Cr2O3
Chemical Name - Chromium(III) oxide / chromium sesquioxidie
Structure - Rhombohedral
Synthesis - Heat potassium dichromate with ammonium chloride.
Interesting Facts - n/a
Veridian
Use - Paint pigment
Formula - Cr2O3 • 2H2O
Chemical Name - Chromium(III) oxide dihydrate
Structure - n/a
Synthesis - 8g boric acid and 3g potassium dichromate are mixed together and heated. They are mixed with cold water, washed and ground and finally washed with hot water before drying.
Interesting Facts - n/a
Cobalt Green
Use - Paint pigment
Formula - CoO • ZnO
Chemical Name - Cobalt(II) oxide and zinc(II) oxide
Structure - n/a
Synthesis - A paste of zinc oxide in water is added to cobalt nitrate/sulfate/chloride. The mixture is heated, ground, washed and dried.
Interesting Facts -
Emerald Green
Use - Paint pigment
Formula - Cu(CH3COO)2 • 3Cu(AsO2)2
Chemical Name - Copper(II) acetoarsenite
Structure - n/a
Synthesis - Verdigris is dissolved in acetic acid and added to a boiling aqueous solution of white arsenic.
Interesting Facts - Discovered in 1814.
Scheele's Green
Use - Paint pigment
Formula - Cu(AsO2)2
Chemical Name - Cupric arsenite / copper(II) arsenite
Synthesis - Tetragonal
Synthesis - White arsenic is dissolved and mixed with copper sulfate solution. A small amount of potassium carbonate is added, and then the precipitate is washed with hot water and dried.
Interesting Facts - Scheele's green was used on the walls of Napoleans bedroom, and when it came into contact with mould it made the atmosphere posinous. Paintings using Scheele's green have been known to cause serious illness and even death to people sharing rooms with them.
Malachite
Use - Paint pigment
Formula - 2CuCO3 • Cu(OH)2
Chemical Name - Copper(II) carbonate
Structure - Monoclinic
Synthesis - From the malachite mineral.
Interesting Facts - n/a
Verdigris
Use - Paint pigment
Formula - Cu(OH)2 • (CH3COO)2 • 5H2O
Chemical Name - Basic copper acetate
Structure - n/a
Synthesis - Anhydrous acetic acid is mixed with copper oxide and water.
Interesting Facts - Was used as a paint pigment by the Romans and found in wall paintings at Pompeii.
Atacamite
Use - Paint pigment
Formula - Cu2(OH3)Cl
Chemical Name - Copper(II) chlroide hydroxide
Structure - Orthorhombic
Synthesis - Atacamite is a mimeral.
Interesting Facts - The mineral is formed by the oxidation of other copper minerals.